Systems for mass producing mail pieces are well known in the art. Such systems are typically used by organizations such as government agencies, banks, insurance companies and utility companies for producing a large volume of specific mailings like benefit payment checks, billing statements, or promotional offers.
Mail pieces are typically processed in large groups called “mail runs.” Several thousand related mail pieces are grouped together in a mail run, with similar types of processing and inserts. Mail runs are typically tracked and managed as a group, and mail runs are conventionally submitted to a delivery service for delivery as a group. In order to gain high volume discounts, it is desirable to comingle and sort mail from different mail runs. Thus, high-value critical mailings, such as government benefit checks, might be mixed with less important mail, such as purely informational notices.
Once a finished mail piece has been formed, it is typically stacked in preparation for transfer to a carrier service, such as the U.S. Postal Service. Often, in order to receive the aforementioned postal discounts, it is advantageous to sort the outgoing mail in accordance postal regulations using known sorting machines, such as the Olympus sorting machines available from Pitney Bowes Inc. Most postal authorities offer large discounts to mailers willing to organize/group mail into batches or trays having a common destination. Typically, discounts are available for batches/trays containing a minimum of two hundred (200) or so mailpieces.
Mailpiece sorters are often employed by service providers, including delivery agents, e.g., the United States Postal Service USPS, entities which specialize in mailpiece fabrication, and/or companies providing sortation services in accordance with the Mailpiece Manifest System (MMS).
Prior to transfer to the delivery service, completed mail runs are typically checked for quality and completeness. Because of the high volume of mail that is handled, occasionally a document submitted to the mail production equipment for processing cannot be accounted for at the output end. The unaccounted for mail pieces may have been mishandled, damaged, destroyed, or misplaced.
There are different costs associated with unaccounted for mail pieces. For example, one cost is the expense of resubmitting and reprocessing the mail piece to ensure that the recipient gets the communication. Another cost may be harm caused if a missing document was accidentally stuffed into the wrong envelope and was sent to the wrong recipient. It is also possible that a recipient may not receive their intended mail, or that they might receive two of the same pieces. Depending on the particular circumstances, mailers will weigh the costs and risks and determine how carefully to balance mail runs. For some types of mail runs, failure to balance mail piece accounts may not be significant. As an example, for a mailing that merely included a department store coupon, a mailer might decide to send out an unbalanced mail run. In this case, the mailer is risking the cost that a recipient might not receive an intended coupon, or perhaps get an extra coupon. This cost most likely would not justify redoing the entire mail run. Rather, the unaccounted mail piece might be reprinted and sent, and the balancing failure could be ignored.
However, if the mail run included financial, medical, or other sensitive information, a mailer may need 100% balancing before submitting a mail run for delivery. The potential harm, and loss of customer trust, if sensitive information were not received, or sent to the wrong recipient, could be very damaging. In practice, some mailers have been known to bear the costs of completely redoing the mail runs when perfect balancing cannot be achieved.
With balancing considerations in mind, mailers want to get maximum postal discounts, and the best way to do that might be to comingle mail runs of critical documents with mail runs of less important documents. However, the effort to balance an entire comingled set of mail run may be prohibitively difficult and time consuming using conventional methods. Two methods for balancing are (1) balancing by count and (2) balancing by identifier. Those two methods are both inadequate for dealing with the large comingled mail set that includes both critical and non-critical mail runs.
Balancing by count is accomplished by comparing the machine counters at the end of the run with an expected count of mail pieces. This approach is complicated when reject pieces are often run through the sorter more than once to retry them. Doubled pieces also create special situations. A “double” occurs when two mail pieces stick together and are processed together in the sorter as one piece. Most sorters attempt to detect doubles, and in such cases the system can correct the count. However, undetected double feeds create a situation where it is often impossible to find the missing mail piece.
The drawback of the balancing by count approach is that there is little that can be done when the counts do not match. This problem becomes particularly acute when large numbers of mail pieces are comingled. In such cases hundreds of thousands of documents could be run through the sorter in a single pass. If the counts are off then there is little choice but to rerun the entire set of mail. If the critical “high value” documents only represent a small fraction of the overall mailing this could be an onerous burden. Since balance by count is based on the final counts it cannot be attempted until the sorter run is completed. This jeopardizes the timeliness of sorter processing since one is never sure whether one will fail to balance and how long it will take to remediate the mail.
Balancing by identifier is accomplished by putting a unique identifier on each piece and having the sorter read that unique identifier off of each piece fed. The identifier might be in the form of a barcode or it might be in the form of a keyline string that is read by an optical character recognition (OCR) system.
Using this method, at the end of the run, the operator can print out a set of reports that list the identifiers not accounted for. The operator must then go through the reject pockets and other pockets on the sorter to find each mail piece.
The biggest issue with the balancing by identifier technique occurs when one identifier is accidentally read as another identifier (i.e. a substitution error). An example of a substitution error might occur if the OCR read a keyline of “12” as a ‘1Z”. In this case one identifier (“1Z”) might appear to have been seen twice and another identifier (“12”) might appear to be missing. The problem with this is that all or some of these pieces involved would have been sorted to their respective sorter pockets, and would be hard to manually find.
Aside from the fact that it does not deal well with substitution errors this technique also has the disadvantage that it usually involves manual manipulation of the mail piece. Pieces where the identifier cannot be read must be out-sorted, so they can be physically collected and “checked off” the list of unaccounted for pieces.
Also this technique is still best applied when the sorter run is complete. There are two reasons for this. The first is that it is because it is confusing to be physically collecting rejects off of the sorter while it is actively running. The second is that there is little point of printing off a report and checking off the spoils when one has not completed the run.